1. Field of the Invention
The present invention relates to a Fischer-Tropsch process using an iron-containing layered material.
2. Prior Art
As explained by M. E. Dry in Catal. Lett., Vol. 7 (1990) 241-252, the most suitable catalytic metals for Fisher Tropsch synthesis, i.e. the production of hydrocarbons from CO and H2, are Fe, Co, and Ru. Of these metals, iron is the least expensive and has the highest selectivity to olefins.
In order to reach a satisfactory selectivity, iron-containing catalysts require a certain level of basicity. This basicity is usually created by the addition of alkali. Unfortunately, alkali is known to migrate over the catalyst surface, enhancing iron sintering. Furthermore, alkali enhances carbon lay-down on the catalyst, leading to deactivation of the catalyst.
Apart from carbon lay-down, also sulphur poisoning might cause deactivation. Furthermore, as a result of diffusion resistance inside the iron particles, the water vapour pressures inside these particles can be relatively high, leading to sintering and/or oxidation of the inner core of the iron particles. Shen et al. disclose the use of calcined and subsequently reduced Mg—Fe anionic clay (Catal. Today 30 (1996) 77-82/J. Solid State Chem. 128 (1997) 73-79) and Ni—Fe anionic clay (Thermochimica Acta 302 (1997)) in a Fischer-Tropsch process.
The present invention provides a method for performing a Fischer-Tropsch process using iron-containing layered materials which is simpler than the method of Shen. It involves fewer reaction steps and/or uses a catalyst that is easier to prepare.